SOLUTION: determine whether the graphs of the equation are parallel, perpendicular, or neither a. y=2x+5 2x+y=9 b. 3x+4y=7 4x=3y-8 please help me figure this out, my teache

Algebra ->  Systems-of-equations -> SOLUTION: determine whether the graphs of the equation are parallel, perpendicular, or neither a. y=2x+5 2x+y=9 b. 3x+4y=7 4x=3y-8 please help me figure this out, my teache      Log On


   

Question 811800: determine whether the graphs of the equation are parallel, perpendicular, or neither
a. y=2x+5
2x+y=9
b. 3x+4y=7
4x=3y-8
please help me figure this out, my teacher gives us take home tests but she does not really do a lesson on anything before she hands us the test. I am not really good at math from the beginning so i am really struggling here. if anyone could please help me out i would really appreciate it! Thank you so much!!!
Found 2 solutions by richwmiller, erica65404:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
parallel-- have the same slope
perpendicular --the slopes multiplied together =-1
neither they cross and aren't perpendicular
a. y=2x+5
2x+y=9
y=-2x+9
not perpendicular nor parallel
meet at
x = 1, y = 7
b. 3x+4y=7
4y=-3x+7
y=-3/4x+7/4
4x=3y-8
3y=4x+8
y=4/3x+8/3
they are perpendicular
-3/4*4/3=-1
x = -11/25, y = 52/25


Answer by erica65404(394) About Me  (Show Source):
You can put this solution on YOUR website!
perpendicular lines have slopes that are inverses.
5%2F1
-1%2F5
These slopes are perpendicular.
Parallel lines have the same slope.
first solve the equations for y

a. y=2x%2B5
slope is 2%2F1
2x%2By=9
y=-2x%2B9
slope is -2%2F1
The slope arent the same or inverses.
neither

b.3x%2B4y=7
4y=-3x%2B7
y=%28-3%2F4%29x%2B%287%2F4%29
slope is -3%2F4
4x=3y-8
4x%2B8=3y
%284%2F3%29x%2B%288%2F3%29=y
The slope is 4%2F3
These slopes are inverses.
perpendicular